scholarly journals Effects of CO<sub>2</sub>-driven ocean acidification on early life stages of marine medaka (<i>Oryzias melastigma</i>)

2015 ◽  
Vol 12 (1) ◽  
pp. 1-20 ◽  
Author(s):  
J. Mu ◽  
F. Jin ◽  
J. Wang ◽  
N. Zheng ◽  
Y. Cong
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Early Life ◽  
Life Stage ◽  
Control Group ◽  
Hatching Rate ◽  
Marine Medaka ◽  
Saturation State ◽  
Oryzias Melastigma ◽  
Co2 Level

Abstract. The potential effects of elevated CO2 level and reduced carbonate saturation state in marine environment on fishes and other non-calcified organisms are still poorly known. In present study, we investigated the effects of ocean acidification on embryogenesis and organogenesis of newly hatched larvae of marine medaka (Oryzias melastigma) after 21 d exposure of eggs to different artificially acidified seawater (pH 7.6 and 7.2, respectively), and compared with those in control group (pH 8.2). Results showed that CO2-driven seawater acidification (pH 7.6 and 7.2) had no detectable effect on hatching time, hatching rate, and heart rate of embryos. However, the deformity rate of larvae in pH 7.2 treatment was significantly higher than that in control treatment. The left and right sagitta areas did not differ significantly from each other in each treatment. However, the mean sagitta area of larvae in pH 7.6 treatment was significantly smaller than that in the control (p = 0.024). These results suggest that although marine medaka might be more tolerant of elevated CO2 than some other fishes, the effect of elevated CO2 level on the calcification of otolith is likely to be the most susceptibly physiological process of pH regulation in early life stage of marine medaka.

scholarly journals Effects of CO<sub>2</sub>-driven ocean acidification on early life stages of marine medaka (<i>Oryzias melastigma</i>)

2015 ◽  
Vol 12 (12) ◽  
pp. 3861-3868 ◽  
Author(s):  
J. Mu ◽  
F. Jin ◽  
J. Wang ◽  
N. Zheng ◽  
Y. Cong
Keyword(s):  
Ocean Acidification ◽  
Early Life ◽  
Environmental Influence ◽  
Hatching Rate ◽  
Life Stages ◽  
Early Life Stages ◽  
Marine Medaka ◽  
Significant Difference ◽  
Co2 Levels ◽  
Oryzias Melastigma

Abstract. The potential effects of high CO2 and associated ocean acidification (OA) in marine fishes and other non-calcified organisms are less well understood. In this study, we investigated the responses of early life stages (ELS) of marine medaka (Oryzias melastigma) exposed to a series of experimental manipulation of CO2 levels. Results showed that CO2-driven seawater acidification (pH 7.6 and pH 7.2) had no detectable effect on hatching time, hatching rate, or heart rate of embryos. However, the deformity rate of larvae in the pH 7.2 treatment was significantly higher than that in the control treatment. There is no significant difference between the left and right otolith areas in each treatment. However, the average otolith area of larvae in the pH 7.6 treatment was significantly smaller than that in the control. Such alterations in the developmental abnormalities and otolith size of marine medaka larvae due to elevated-CO2 levels suggests that this species will be increasingly challenged by future OA. Further studies of the impacts of OA on marine fish to assess whether or not the environmental influence in one generation can affect the later life history and the phenotype of subsequent generations are needed.

scholarly journals Benthic buffers and boosters of ocean acidification on coral reefs

2013 ◽  
Vol 10 (2) ◽  
pp. 1831-1865 ◽  
Author(s):  
K. R. N. Anthony ◽  
G. Diaz-Pulido ◽  
N. Verlinden ◽  
B. Tilbrook ◽  
A. J. Andersson
Keyword(s):  
Ocean Acidification ◽  
Time Of Day ◽  
High Flow ◽  
Net Community Production ◽  
Reef Environment ◽  
Saturation State ◽  
Low Co2 ◽  
Coral Reef Environment ◽  
Co2 Level ◽  
Community Production

Abstract. Ocean acidification is a threat to marine ecosystems globally. In shallow-water systems, however, ocean acidification can be masked by benthic carbon fluxes, depending on community composition, seawater residence time, and the magnitude and balance of net community production (pn) and calcification (gn). Here, we examine how six benthic groups from a coral reef environment on Heron Reef (Great Barrier Reef, Australia) contribute to changes in seawater aragonite saturation state (Ωa). Results of flume studies showed a hierarchy of responses across groups, depending on CO2 level, time of day and water flow. At low CO2 (350–450 μatm), macroalgae (Chnoospora implexa), turfs and sand elevated Ωa of the flume water by around 0.10 to 1.20 h−1 – normalised to contributions from 1 m2 of benthos to a 1 m deep water column. The rate of Ωa increase in these groups was doubled under acidification (560–700 μatm) and high flow (35 compared to 8 cm s−1). In contrast, branching corals (Acropora aspera) increased Ωa by 0.25 h−1 at ambient CO2 (350–450 μatm) during the day, but reduced Ωa under acidification and high flow. Nighttime changes in Ωa by corals were highly negative (0.6–0.8 h−1) and exacerbated by acidification. Calcifying macroalgae (Halimeda spp.) raised Ωa by day (by around 0.13 h−1), but lowered Ωa by a similar or higher amount at night. Analyses of carbon flux contributions from four different benthic compositions to the reef water carbon chemistry across Heron Reef flat and lagoon indicated that the net lowering of Ωa by coral-dominated areas can to some extent be countered by long water residence times in neighbouring areas dominated by turfs, macroalgae and potentially sand.

scholarly journals Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma)

2013 ◽  
Vol 70 (4) ◽  
pp. 812-822 ◽  
Author(s):  
Thomas P. Hurst ◽  
Elena R. Fernandez ◽  
Jeremy T. Mathis
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Larval Growth ◽  
Walleye Pollock ◽  
Growth Potential ◽  
Theragra Chalcogramma ◽  
Walleye Pollock Theragra Chalcogramma ◽  
Co2 Levels ◽  
Critical Resource ◽  
Co2 Level

Abstract Hurst, T. P., Fernandez, E. R., and Mathis, J. T. 2013. Effects of ocean acidification on hatch size and larval growth of walleye pollock (Theragra chalcogramma). – ICES Journal of Marine Science, 70: 812–822. Rising atmospheric concentrations of CO2 are predicted to decrease the pH of high-latitude oceans by 0.3–0.5 units by 2100. Because of their limited capacity for ion exchange, embryos and larvae of marine fishes are predicted to be more sensitive to elevated CO2 than juveniles and adults. Eggs and larvae of walleye pollock (Theragra chalcogramma) were incubated across a broad range of CO2 levels (280–2100 µatm) to evaluate sensitivity in this critical resource species. Slightly elevated CO2 levels (∼450 µatm) resulted in earlier hatching times, but differences among egg batches were greater than those observed across CO2 treatments. Egg batches differed significantly in size-at-hatch metrics, but we observed no consistent effect of CO2 level. In three independent experiments, walleye pollock were reared at ambient and elevated CO2 levels through the early larval stage (to ∼30 days post-hatch). Across trials, there were only minor effects of CO2 level on size and growth rate, but fish in the ambient treatments tended to be slightly smaller than fish reared at elevated CO2 levels. These results suggest that growth potential of early life stages of walleye pollock is resilient with respect to the direct physiological effects of ocean acidification.

scholarly journals Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish

2015 ◽  
Vol 73 (3) ◽  
pp. 981-990 ◽  
Author(s):  
Thomas P. Hurst ◽  
Benjamin J. Laurel ◽  
Jeremy T. Mathis ◽  
Lauren R. Tobosa
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Larval Growth ◽  
Gulf Of Alaska ◽  
Growth Responses ◽  
Egg Survival ◽  
Co2 Levels ◽  
Co2 Level ◽  
The One ◽  
Eggs And Larvae

Abstract The Bering Sea and Gulf of Alaska support a number of commercially important flatfish fisheries. These high latitude ecosystems are predicted to be most immediately impacted by ongoing ocean acidification, but the range of responses by commercial fishery species has yet to be fully explored. In this study, we examined the growth responses of northern rock sole (Lepidopsetta polyxystra) eggs and larvae across a range of CO2 levels (ambient to 1500 µatm) to evaluate the potential sensitivity to ocean acidification. Laboratory-spawned eggs and larvae were reared at 8°C in a flow-through culture system in which CO2 levels were maintained via computer-controlled injection of CO2 into a seawater conditioning tank. Overall, we observed only minor effects of elevated CO2 level on sizes of northern rock sole larvae. Size at hatch differed among offspring from four different females, but there was no significant effect of CO2 level on egg survival or size at hatch. In three separate larval growth trials, there was little effect of CO2 level on growth rates through the first 28 d post-hatch (DPH). However, in the one trial extended to 60 DPH, fish reared at the highest CO2 level had lower condition factors after 28 DPH, suggesting that larvae undergoing metamorphosis may be more sensitive to environmental hypercapnia than earlier pre-flexion stages. These results suggest that while early life stages of northern rock sole are less sensitive to ocean acidification than previously examined flatfish, they may be more sensitive to elevated CO2 levels than a previously studied gadid with a similar geographic range.

scholarly journals Effect of Terbuthylazine-2-hydroxy at Environmental Concentrations on Early Life Stages of Common Carp (Cyprinus carpioL.)

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Josef Velisek ◽  
Alzbeta Stara ◽  
Dalibor Koutnik ◽  
Jana Machova
Keyword(s):  
Common Carp ◽  
Early Life ◽  
Life Stage ◽  
Early Life Stage ◽  
Control Fish ◽  
Control Group ◽  
Embryo Viability ◽  
Sod Activity ◽  
Environmental Concentration ◽  
Effect Concentration

The aim of the study was to investigate effects of the triazine’s herbicide terbuthylazine-2-hydroxy on early life stage of common carp (Cyprinus carpioL.) through antioxidant indices, mortality, growth, development, and histopathology. Based on accumulated mortality in the experimental groups, lethal concentrations of terbuthylazine-2-hydroxy were estimated at 35-day LC50 = 10.9 mg/L terbuthylazine-2-hydroxy. By day 15, fish were exposed to 3.5 mg/L and by day 26, fish were exposed to 0.0029 mg/L; real environmental concentration in Czech rivers, 0.07 mg/L, 1.4 mg/L, and 3.5 mg/L terbuthylazine-2-hydroxy, showed significantly lower mass and total length compared with controls. Based on inhibition of growth in the experimental groups, lowest observed effect concentration (LOEC) = 0.002 mg/L terbuthylazine-2-hydroxy and no observed effect concentration (NOEC) = 0.0001 mg/L terbuthylazine-2-hydroxy. No significant negative effects on hatching or embryo viability were demonstrated at the concentrations tested, but significant differences in early ontogeny among groups were noted. Fish from the two highest tested concentrations showed a dose-related delay in development compared with the controls. Total superoxide dismutase (SOD) activity was significant lower in all groups testedly for terbuthylazine-2-hydroxy compared with the control group. At concentrations of 1.4 and 3.5 mg/L damage to caudal kidney tubules when compared to control fish was found.

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